Following the fast development in technology, transportation vehicles are drastically improved accordingly. At the present time, the number of automobiles has become one of the national economic indexes in developing countries.
In order to provide weather protective effects a car must basically be well enclosed. For best performance in the most economical way, it requires a minimized car body provided with a maximized inner space.
When seating in a driver's seat to drive a car for a certain period of time, one may feel uncomfortable due to confined space, and may feel exhausted and tired out very quickly. In such a moving and narrow space, it is rather difficult to protect against the weather. For example, during the hot summertime, the summer heat is transmitted into the inner space of a car through car roof after the car is exposed to the sun for a certain period of time, and the inner space of the car is immediately filled with steaming heat. During the cold winter, the outside cold temperature is induced into the car through car roof to make the inner space of the car become icy cold.
Regular car roof trim board structure consists of one layer of PU or EVA sheet attached to the metal plate roof to buffer heat transmission. In order to provide comfortable temperature, regular cars are usually equipped with an air conditioner to regulate the temperature according to outside weather. However, it wastes a lot of power and consumes extra gasoline since regular car roof trim structure couldn't provide good heat insulation effect. Because regular car roof insulation layer is made of open cell PU or EVA foam sheet, after having been indirectly radiated by sunlight for a certain period of time, it absorbs heat and transmits downward about 40% of the heat absorbed into the car. In the winter season, it transmit the heat in reverse direction, that is, it transmits the heat from human body to the outside beyond the car.
In view of said problem, the present invention provides a modified car roof trim board structure to provide better heat insulation effect.